Stats

Question 1

False negative

Answer 1

False negative = no. Individuals who have condition but were incorrectly identified as NOT having it / total no. Individuals who have the condition.

Question 2

False positive

Answer 2

False positive = no. Individuals who do NOT have the condition but incorrectly identified as having it / total no. Individuals who do NOT have the condition

Question 3

Sensitivity

Answer 3

Sensitivity = no. Individuals with condition who test positive / total no. Individuals with the condition

Question 4

Specificity

Answer 4

Specificity = no. Individuals without condition who test negative/ total no. Individuals without the condition

Question 5

Case control study

Answer 5

Looking at 2 sets of participants - one group has condition of interest and the other does not

Question 6

Case series study

Answer 6

Looks at a group of patients with a similar experience - diagnosis, treatment, etc.

Question 7

Cross sectional study

Answer 7

Analyses data from a population/representative subset at a single point in time

Question 8

Number needed to treat

Answer 8

NNT = 1 / (risk reduction)

where risk reduction is the absolute difference in event rates between the treatment and control groups.

Question 9

Relative risk

Answer 9

risk in the group exposed to drug / risk in those not exposed

Question 10

Levels of studies 1-5

Answer 10

1: Met analyses/ systems rvs
2. RCT
3. Retrospective cohort study
4. Case series
5. Expert opinion/single case report